Prior art balers of this type generally have a bale forming chamber defined by an apron comprising an array of side-by-side belts, transverse slats trained on chains, a plurality of rolls or a combination of these various elements, e.g., rolls and belts. Crop material, such as hay, is picked up from the ground as the baler traverses the field, fed into a fixed or adjustable chamber where it is rolled up to form a compact cylindrical bale. The formed bale is wrapped in its compacted form while still inside the bale forming chamber by net, twine or the like, prior to ejecting the bale from the chamber onto the ground for subsequent handling.
Exemplary of prior art round balers of the type generally referred to above is the baler disclosed in U.S. Pat. No. 5,036,642, mentioned above. This baler includes a mechanism for dispensing a net wrapping material into a bale forming chamber to circumferentially wrap a formed cylindrical bale. The dispensing mechanism includes a unique net insertion arrangement including a grasping portion for inserting the net tail into the chamber after the bale is formed. In net wrapping systems of this type it is crucial that a tail of adequate length is provided to assure initiation of the qrasping operation. When the tail is placed in the chamber it is pinched between the bale and the bale forming elements that rotate the bale during wrapping. A critical length is determined for consistent grasping of the tail and to maintain this consistency the tail length must be continually at the critical length.
Problems have been encountered in past attempts to accomplish the above advantages because the net being issued from the supply roll and guided to the grasping portion of the dispensing mechanism required a high friction clamp pressure for various reasons. Accordingly, the net pulling force provided by virtue of the tail being fed into the nip between the bale and the apron to draw it around the bale a it is held between the moving bale and apron must be increased. When an increased grasping force of this nature is required, net wrap starting is not consistent due to variations in the pulling force as the net material is being fed into a nip that varies due to the nature of the crop material of the formed bale. In this particular dispensing mechanism, comprising opposing flat clamping members through which the net is guided, it is important for the net to be maintained at the minimal level of friction force required for smooth feeding of the net downstream of the flat clamping members and thereby provide consistent net starting.